Linksys' Velop mesh routers can detect intruders using WiFi
 

If you want to improve your home security but would rather not add cameras or sensors to your living space, you could try using your router instead. Linksys has introduced a new motion sensing subscription service, Linksys Aware, which uses data from...

https://www.engadget.com/2019/10/08/...sensing-velop/